Field of Invention
The present invention relates to a breathing apparatus that uses ultraviolet light emitting diodes to reduce risk from airborne pathogens.
Description of Related Art
Acute respiratory infection (ARI), which causes millions deaths every year, is the number one cause of death in the developing world, and number three cause of death worldwide. In the event of an ARI pandemic or other emerging respiratory disease such as severe acute respiratory syndrome (SARS), measures are preferably taken immediately to reduce the infection rate, rather than wait for a targeted vaccine or antiviral drug to be developed. Wearing a facemask is a widely accepted, non-pharmaceutical method to reduce the risk of respiratory infection.
Examples of common facemasks include disposable surgical facemasks and N95 respirators. This type of facemask reduces transmission of airborne pathogens by preventing a person from directly touching his nose and mouth with dirty hands and by containing large liquid droplets expelled during sneezing or coughing. This type of facemask is unable to disinfect the air being inhaled or exhaled, and typically cannot block airborne viruses, most of which are smaller than 0.3 microns and can pass through the pores in the fabrics of this type of facemask. In addition, because the main air passageway of the facemask is blocked by one or more layers of fabric, this type of facemask is generally uncomfortable to wear, which may discourage people from using facemasks. Furthermore, if the mask is not face-fitted, a significant amount of air can leak through the periphery of the mask, significantly reducing the mask's effectiveness and leading to other inconveniences such as fogging of lenses in cold weather for eye-glass wearers from leakage of moist air.
FIG. 1 illustrates a chemical and biological protection mask described in more detail in US 2010/0132715. The gas mask assembly 2 generally comprises a molded mask portion 10 containing a frontal one-way exhalation valve 20 and one or more adjacent inhalation apertures 12. The inhalation aperture 12 is equipped with a push-and-twist receptacle 14. A UV-illumination tube 50 is interposed between the inhalation aperture 12 and a filter assembly 40, which may provide mechanical filtration capabilities, such as HEPA-type or charcoal filters. The UV illumination tube 50 is a short multi-part cylinder, approximately 2-5″, with mating push-and-twist receptacle/seats at each end for seating the filter assembly 40 and insertion into receptacle 14 of mask 10. The UV illumination tube 50 further comprises a cylindrical aluminum outer shell, and a cylindrical plastic insert that seats a plurality of elongate axially-aligned circuit boards each carrying a plurality of surface-mounted LED UV lights disposed inwardly toward the centerline of the tube 50. The UV illumination tube 50 is centrally unobstructed and incoming air from filter assembly 40 remains free to pass into the inhalation aperture 12 of the mask 10. While passing through the tube's length, the air is illuminated with high-intensity shortwave ultraviolet light from the LEDs and is thereby fully filtered and irradiated for combined chemical and biological protection. Power for the LEDs is derived from an on-board battery which may be built into the UV illumination tube 50 or the mask 10 (requiring slide-connectors along the lip of the tube 50), and/or from a solar cell likewise mounted on the UV illumination tube 50 or the mask 10. Preferably, an on/off detent switch 52 for the LEDs is provided on the tube 50 as well.